Surgical end effectors and pulley assemblies thereof

ABSTRACT

An end effector of a surgical tool includes a first jaw and a second jaw rotated by a driving pulley. A first driven pulley is attached to the first jaw and a second driven pulley is attached to the second jaw. A first end portion of a first cable is connected to a first radial side of the first driven pulley, a second end portion of the first cable is connected to a second radial side of the second driven pulley, and an intermediate portion of the first cable is connected to the driving pulley. A first end portion of a second cable is connected to a first radial side of the second driven pulley, a second end portion of the second cable is connected to a second radial side of the first driven pulley, and an intermediate portion of the second cable is connected to the driving pulley.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation Application which claims the benefit of and priority to U.S. patent application Ser. No. 15/116,350, filed on Aug. 3, 2016, which is a U.S. National Stage Application filed under 35 U.S.C. § 371(a) of International Patent Application Serial No. PCT/US2014/064009, filed Nov. 5, 2014, which claims the benefit of each of U.S. Provisional Patent Application Ser. No. 61/938,728, filed Feb. 12, 2014, and U.S. Provisional Patent Application Ser. No. 61/938,732, filed Feb. 12, 2014, the entire disclosure of each of which are incorporated by reference herein.

BACKGROUND

Robotic surgical systems have been used in minimally invasive medical procedures. Some robotic surgical systems included a console supporting a robot arm, and at least one end effector such as forceps or a grasping tool including jaws for capturing tissue therebetween. The at least one end effector was mounted to the robot arm. During a medical procedure, the end effector was inserted into a small incision (via a cannula) or a natural orifice of a patient to position the end effector at a work site within the body of the patient.

Cables extended from the console, through the robot arm, and connected to the end effector. In some instances, the cables were actuated by means of motors that were controlled by a processing system including a user interface for a surgeon or clinician to be able to control the robotic surgical system including the robot arm and/or the end effector. The cables connected to a pulley assembly that transferred torque to drive the actuation of the end effector.

In some instances, surgical procedures may require fine control of the end effector to grasp tissue for dissection and/or to spread tissue surfaces for deep tissue access. Accordingly, there is a need for surgical tools that are able to provide precisely controlled forces applied by jaws of an end effector of a robotic surgical system.

SUMMARY

Jaws at the end of surgical robotics tools, such as forceps or scissor cutting tools, may be driven by a pulley assembly including pulleys and cables. In accordance with an aspect of the present disclosure, an end effector of a surgical tool comprises a first jaw and a second jaw each being rotatable about a first axis. A first driven pulley is attached to the first jaw and a second driven pulley is attached to the second jaw. The first and second driven pulleys are rotatable about the first axis. Each driven pulley includes a first radial side and a second radial side. A driving pulley is rotatable about a second axis. A first cable has a first end portion, a second end portion, and an intermediate portion. The first end portion is connected to the first radial side of the first driven pulley. The second end portion is connected to the second radial side of the second driven pulley. The intermediate portion is connected to the driving pulley. A second cable has a first end portion, a second end portion, and an intermediate portion. The first end portion is connected to the first radial side of the second driven pulley. The second end portion is connected to the second radial side of the first driven pulley. The intermediate portion is connected to the driving pulley. A rotation of the driving pulley about the second axis rotates the driven pulleys in opposite directions about the first axis to open or close the jaws.

In some embodiments, a rotation of the driving pulley in a first direction about the second axis may rotate the first and second driven pulleys via the first cable. A rotation of the driving pulley in a second direction, opposite the first direction, may rotate the first and second driven pulleys via the second cable.

In aspects of the present disclosure, during rotation of the driving pulley in the first direction, the first cable may be in a tensioned condition and the second cable may be in a slack condition. During rotation of the driving pulley in the second direction, the first cable may be in a slack condition and the second cable may be in a tensioned condition.

In another aspect of the present disclosure, the intermediate portions of the first and second cables may be connected to a common point of the driving pulley or may be connected to different points of the driving pulley. It is contemplated that the intermediate portions of the first and second cables may be crimped to the driving pulley.

In some instances, the first end portion of the first cable and the second end portion of the second cable may be parallel, and in other instances the first end portion of the second cable and the second end portion of the first cable may cross. In other instances the respective end portions of the cables may be perpendicular instead of parallel or may be positioned at different angles that are neither parallel nor perpendicular.

In some embodiments, a proximal end of the first jaw may be fixedly attached to a circumferential edge of the first drive pulley and a proximal end of the second jaw may be fixedly attached to a circumferential edge of the second drive pulley.

In aspects of the present disclosure, the first and second jaws may be in flush engagement with one another. It is contemplated that the first axis may be spaced a lateral distance from the second axis. It is further contemplated that the first and second cables may be connected to the driving pulley at a location off-set a radial distance from the second axis.

In embodiments, the driving pulley may support an anchor member, and the intermediate portions of the first and second cables may each be looped through the anchor member of the driving pulley. The anchor member may include a hook that can be attached to a circumferential edge of the driving pulley.

In accordance with another aspect of the present disclosure, a pulley assembly for actuating a first jaw and a second jaw is provided. The pulley assembly comprises a first driven pulley configured to be attached to the first jaw and a second driven pulley configured to be attached to the second jaw. The first and second driven pulleys are rotatable about a first axis. Each driven pulley includes a first radial side and a second radial side. A driving pulley is rotatable about a second axis. A first cable has a first end portion, a second end portion, and an intermediate portion. The first end portion is connected to the first radial side of the first driven pulley. The second end portion is connected to the second radial side of the second driven pulley. The intermediate portion is connected to the driving pulley. A second cable has a first end portion, a second end portion, and an intermediate portion. The first end portion is connected to the first radial side of the second driven pulley. The second end portion is connected to the second radial side of the first driven pulley. The intermediate portion is connected to the driving pulley. A rotation of the driving pulley about the second axis rotates the first and second driven pulleys in opposite directions about the first axis.

In aspects of the present disclosure, a rotation of the driving pulley in a first direction about the second axis may rotate the first and second driven pulleys via the first cable. A rotation of the driving pulley in a second direction, opposite the first direction, may rotate the first and second driven pulleys via the second cable. In embodiments, during rotation of the driving pulley in the first direction, the first cable may be in a tensioned condition and the second cable may be in a slack condition. During rotation of the driving pulley in the second direction, the first cable may be in a slack condition and the second cable may be in a tensioned condition.

In some of these aspects, the intermediate portions of the first and second cables may be connected to a common point of the driving pulley or may be connected to different points of the driving pulley. In some instances, the first and second cables may be crimped to the driving pulley.

In some of the aforementioned aspects, the first end portion of the first cable and the second end portion of the second cable may be parallel, and the first end portion of the second cable and the second end portion of the first cable may cross. In other instances the respective end portions of the cables may be perpendicular instead of parallel or may be positioned at different angles that are neither parallel nor perpendicular.

In accordance with yet another aspect of the present disclosure, another pulley assembly for actuating a first jaw and a second jaw is provided. The pulley assembly may include at least two driven pulleys. Each driven pulley may be coupled to a respective jaw and each driven pulley may include at least two radial sides.

The pulley assembly may also include a driving pulley rotatable about a different axis from the driven pulleys and at least two cable sections. Each cable section may couple different radial sides of each driven pulley to the driving pulley. A directional change in rotation of the driving pulley may relieve a tension in at least two first cable sections coupled to different radial sides of at least two of the driven pulleys and may apply a tension to at least two second cable sections coupled to opposite radial sides of the driven pulleys than the first two cable sections.

In some instances, a first cable section may be coupled between a first radial side of a first driven pulley and the driving pulley. A second cable section may be coupled between a second radial side of the first driven pulley and the driving pulley. A third cable section may be coupled between a first radial side of a second driven pulley and the driving pulley. A fourth cable section may be coupled between a second radial side of the second driven pulley and the driving pulley.

The first and the fourth cable sections may be tensioned and the second and the third cable sections may be slackened when the driving pulley is rotated in a first direction. The first and the fourth cable sections may be slackened and the second and the third cable sections may be tensioned when the driving pulley is rotated in a second direction. In some instances, at least two of the cable sections may be part of a single continuous cable.

The first and the second cable sections may be part of a first single continuous cable and the third and the fourth cable sections may be part of a second single continuous cable. The first and the fourth cable sections may be part of a first single continuous cable and the second and the third cable sections may be part of a second single continuous cable. In other instances, each of the cable sections may be a separate cable from the other cable sections. In other instances, two of the cable sections may be part of a single continuous cable and two of the cable sections may be separate cables.

Further details and aspects of exemplary embodiments of the present disclosure are described in more detail below with reference to the appended figures.

As used herein, the terms parallel and perpendicular are understood to include relative configurations that are substantially parallel and substantially perpendicular, such as up to about + or −10 degrees from true parallel and true perpendicular.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present disclosure are described herein with reference to the accompanying drawings, wherein:

FIG. 1A is a schematic illustration of a medical work station and operating console in accordance with the present disclosure;

FIG. 1B is a schematic, perspective view of a motor of a control device of the medical work station of FIG. 1A, having a cable connected thereto;

FIG. 2 is a schematic plan view, with parts separated, of a surgical end effector, according to an embodiment of the present disclosure, illustrating jaws and a pulley assembly thereof;

FIG. 3A is a perspective view of the pulley assembly of the end effector shown in FIG. 2;

FIG. 3B is a perspective view of an alternate pulley assembly to that shown in FIG. 3A;

FIG. 4 is a perspective, cutaway view of the end effector shown in FIG. 2 with the jaws disposed in a closed configuration;

FIG. 5 is a perspective, cutaway view of the end effector shown in FIG. 2 with the jaws disposed in an open configuration; and

FIG. 6 is a schematic plan view, with parts separated, of a surgical end effector, according to another embodiment of the present disclosure, illustrating jaws and a pulley assembly thereof.

DETAILED DESCRIPTION

Embodiments of the presently disclosed surgical end effectors and methods of actuating the same are described in detail with reference to the drawings, in which like reference numerals designate identical or corresponding elements in each of the several views. As used herein the term “distal” refers to that portion of the jaws and/or pulley assembly that is closer to a surgical site, while the term “proximal” refers to that portion of the jaws and/or pulley assembly that is farther from the surgical site.

Referring initially to FIGS. 1A and 1B, a medical work station is shown generally as work station 1 and may include one or more robot arms 2, 3; a control device 4; and an operating console 5 coupled with control device 4. Operating console 5 includes a display device 6, which is set up in particular to display three-dimensional images and/or video; and manual input devices 7, 8, by means of which a person (not shown), for example a surgeon, is able to telemanipulate robot arms 2, 3 in a first operating mode, as known in principle to a person skilled in the art.

Each of the robot arms 2, 3 includes an attaching device 9, 11, to which may be attached, for example, a surgical tool “ST” supporting an end effector 100, in accordance with any one of several embodiments disclosed herein, as will be described in greater detail below.

Robot arms 2, 3 may be driven by electric drives (not shown) that are connected to control device 4. Control device 4 (e.g., a computer) is set up to activate the drives, in particular by means of a computer program, in such a way that robot arms 2, 3, their attaching devices 9, 11 and thus the surgical tool (including end effector 100) execute a desired movement according to a movement defined by means of manual input devices 7, 8. Control device 4 may also be set up in such a way that it regulates the movement of robot arms 2, 3 and/or of the drives.

Medical work station 1 is configured for use on a patient 13 lying on a patient table 12 to be treated in a minimally invasive manner by means of end effector 100. Medical work station 1 may also include one or more robot arms 2, 3, the additional robot arms likewise being connected to control device 4 and being telemanipulatable by means of operating console 5. A medical instrument or surgical tool (including an end effector 100) may also be attached to the additional robot arm. Medical work station 1 may include a database 14, in particular coupled to with control device 4, in which are stored for example pre-operative data from patient 13 and/or anatomical atlases.

Reference may be made to U.S. Patent Publication No. 2012/0116416, filed on Nov. 3, 2011 (now U.S. Pat. No. 8,828,023), entitled “Medical Workstation,” the entire content of which is incorporated herein by reference, for a detailed discussion of the construction and operation of medical work station 1.

Control device 4 may control a plurality of motors (Motor 1 . . . n) with each motor configured to wind-up or let out a length of cable “C” (FIG. 1B) extending to end effector 100 of the surgical tool. The distal end of each cable “C” is wrapped around a driving pulley 140 of end effector 100 in the manner of a capstan to drive a rotation of driving pulley 140 as shown, for example, in FIG. 2. In use, as cables “C” are wound-up and let out, cables “C” effect operation and/or movement of each end effector 100 of the surgical tool via pulley assembly 120, as described in further detail herein below. It is contemplated that control device 4 coordinates the activation of the various motors (Motor 1 . . . n) to coordinate a winding-up or letting out a length of a respective cable “C” in order to coordinate an operation and/or movement of a respective end effector. Although FIG. 1B shows a single cable “C” that is wound up or let out by a single motor, in some instances two or more cables or two ends of a single cable may be wound up or let out by a single motor. For example, in some instances, two cables or cable ends may be coupled in opposite directions to a single motor so that as the motor is activated in a first direction, one of the cables winds up while the other cable lets out. Other cable configurations may be used in different embodiments.

Turning now to FIGS. 2-5, an end effector in accordance with an embodiment of the present disclosure is generally designated as 100. End effector 100 includes a first jaw 102 a and a second jaw 102 b. First and second jaws 102 a, 102 b are each rotatable or pivotable relative to one another. Each jaw 102 a, 102 b has a respective proximal end 104 a, 104 b and a respective distal end 106 a, 106 b. Each proximal end 104 a, 104 b is fixedly attached to first and second driven pulleys 122 a, 122 b, respectively, as described in further detail herein below. Each proximal end 104 a, 104 b of jaws 102 a, 102 b can be integrally connected to and/or monolithically formed with a circumferential edge of driven pulleys 122 a, 122 b, respectively. Each distal end 106 a, 106 b of jaws 102 a, 102 b defines a respective grip or toothed portion 108 a, 108 b in juxtaposed relation to one another. In use, as will be described in greater detail below, as driving pulley 140 is rotated in one of a clockwise and counter clockwise direction, jaws 102 a, 102 b will be caused to rotate, moving jaws 102 a, 102 b from a first, open configuration in which jaws 102 a, 102 b may receive tissue therebetween to a second, closed configuration in which jaws 102 a, 102 b may grasp tissue.

End effector 100 includes a pulley assembly 120 disposed therein for actuating jaws 102 a, 102 b of end effector 100. Pulley assembly 120 includes a first driven pulley 122 a, a second driven pulley 122 b, a driving pulley 140, a first cable “C1,” and a second cable “C2.” In FIG. 3A, cables C1 and C2 are each continuous cables that may have different cable sections, such as section 51 on cable C1 running from anchor member 180 a on driven pulley 122 a to anchor member 150 on driving pulley 140 and section S2 on cable C1 running from anchor member 150 to anchor member 180 b on driven pulley 122 b. Cable C2 may include cable sections S3 running from anchor member 182 b on driven pulley 122 a to anchor member 150 and section S4 running from anchor member 150 to anchor member 182 a on driven pulley 122 b.

In another embodiment that is a variation of that shown in FIG. 3A, cables C1 and C2 may also be continuous cables that may be attached to pulleys 122 a, 122 b, and 140 in a different manner. For example, continuous cable C1 may include a first section running from anchor member 180 a on driven pulley 122 a to anchor member 150 on driving pulley 140 (similar to section 51 in FIG. 3A) and a second section running from anchor member 150 to anchor member 182 a on driven pulley 122 b (similar to section S4 in FIG. 3A). Continuous cable C2 may include a first section running from anchor member 180 b on driven pulley 122 b to anchor member 150 (similar to section S2 in FIG. 3A) and a second section running from anchor member 150 to anchor member 182 b on driven pulley 122 a (similar to section S3 in FIG. 3A).

This configuration may result in a tensioning of a first section of cables C1 and C2 during a rotation of the driving pulley 140 in a first direction as well as a slacking of the other second section of cables C1 and C2. A tensioning of the second sections of cables C1 and C2 and a slacking of the first sections of cables C1 and C2 may occur when rotating the driving pulley 140 in the opposite direction. Other cable routings may be possible in different embodiments.

FIG. 3B shows another embodiment in which continuous cables C1 and C2 are replaced with four non-continuous sections of cable S5 to S8. In FIG. 3B, cable section S5 runs from anchor member 180 a on driven pulley 122 a to anchor member 151 on driving pulley 140. Cable section S6 runs from a different anchor member 152 on driving pulley 140 to anchor member 180 b on driven pulley 122 b. Cable section S7 runs from anchor member 182 b on driven pulley 122 a to anchor member 153 on driving pulley 140. Cable section S8 runs from anchor member 153 on driving pulley 140 to anchor member 182 a on driven pulley 122 b. Cables and/or cable sections may be connected to the same or different anchor members on the driving pulley 140 in different embodiments.

In embodiments, jaws 102 a, 102 b may be detachably engaged to driven pulleys 122 a, 122 b via a hinge, clips, buttons, adhesives, ferrule, snap-fit, threaded, and/or other engagement.

Each driven pulley 122 a, 122 b has a central opening 124 a, 124 b formed therein configured for disposal or receipt of a pivot pin (not shown) therein. Central openings 124 a, 124 b of each driven pulley 122 a, 122 b are in coaxial alignment with one another. A first axis “X1” extends through central openings 124 a, 124 b of first and second driven pulleys 122 a, 122 b. First and second driven pulleys 122 a, 122 b are disposed adjacent to one another and are rotatable relative to one another about first axis “X1.” In some embodiments, driven pulleys 122 a, 122 b may be in abutting relation to one another or in spaced apart relation to one another, along first axis “X1.” As mentioned above, first driven pulley 122 a supports jaw 102 a and second driven pulley 122 b supports jaw 102 b such that jaws 102 a, 102 b rotate with driven pulleys 122 a, 122 b about first axis “X1.”

Driven pulleys 122 a, 122 b have a circular configuration and each define a circumferential edge 126 a, 126 b. Circumferential edges 126 a, 126 b each define an arcuate channel or groove 128 a, 128 b extending along a circumference of each driven pulley 122 a, 122 b. Channel or groove 128 a, 128 b is configured for receipt of one of cables “C1,” “C2,” as described in further detail herein below. In embodiments, driven pulleys 122 a, 122 b are variously configured, such as, for example, oval, oblong, tapered, arcuate, uniform, non-uniform and/or variable.

First driven pulley 122 a includes a first radial side 130 a and a second radial side 132 a each defining a semicircular portion of first driven pulley 122 a, as demarcated by dotted line “L1” in FIG. 2. First and second radial sides 130 a, 132 a each include one-half of circumferential edge 126 a of first driven pulley 122 a. Second driven pulley 122 b includes a first radial side 130 b and a second radial side 132 b each defining a semicircular portion of second driven pulley 122 b, as demarcated by dotted line “L2” in FIG. 2. First and second radial sides 130 b, 132 b of second driven pulley 122 b include one-half of circumferential edge 126 b of second driven pulley 122 b.

Pulley assembly 120 further includes a driving pulley 140, similar to first and second driven pulleys 122 a, 122 b described herein above. Driving pulley 140 is spaced a lateral distance from first and second driven pulleys 122 a, 122 b. Cable “C,” connected to motor (Motor 1 . . . n), may be wrapped at least once around driving pulley 140, in the manner of a capstan so as to not interfere with first and second cables “C1,” “C2.” Driving pulley 140 includes a central opening 141 formed therein. A second axis “X2” passes through central opening 141, is spaced a lateral distance from first axis “X1,” and may run parallel to first axis “X1” in some instances. In other instances, the second axis “X2” may be offset from the first axis “X1” so that it runs at other non-parallel angles to the first axis “X1,” such as perpendicular to the first axis.

Driving pulley 140 has a circular configuration and defines a circumferential edge 142. Circumferential edge 142 defines an arcuate channel or groove 144 extending along a circumference of driving pulley 140. Channel or groove 144 is configured for disposal of each of cables “C1,” “C2.” Driving pulley 140 includes a first radial side 146 and a second radial side 148 each defining a semicircular portion of driving pulley 140, as demarcated by dotted line “L3” in FIG. 2. First and second radial sides 146, 148 each include one-half of circumferential edge 142 of driving pulley 140.

Driving pulley 140 supports an anchor member 150 attached to a proximal-most portion of circumferential edge 142. Anchor member 150 secures both cables “C1,” “C2” to drive pulley 140 such that, as driving pulley 140 is rotated, cables “C1,” “C2” move therewith. In embodiments, anchor member 150 may be a hook onto which cables “C1,” “C2” are attached. In other embodiments, anchor member 150 may be a crimp that secures cables “C1,” “C2” to circumferential edge 142 of driving pulley 140.

In use, a rotation of driving pulley 140 about second axis “X2” via motor (Motor 1 . . . n) and cable “C” causes first and second driven pulleys 122 a, 122 b to rotate, via cables “C1,” “C2,” in opposing directions about first axis “X1” to open or close first and second jaws 102 a, 102 b, which are attached thereto.

Pulley assembly 120 may further includes a first cable “C1” and a second cable “C2.” First cable “C1” and second cable “C2” each have a first end portion 160 a, 160 b, a second end portion 162 a, 162 b, and an intermediate portion or looped portion 164 a, 164 b. First and second cables “C1,” “C2” are connected to first and second driven pulleys 122 a, 122 b and driving pulley 140 such that first end portion 160 a of first cable “C1” and second end portion 162 b of second cable “C2” are substantially parallel, and first end portion 160 b of second cable “C2” and second end portion 162 a of first cable “C1” cross, as shown in FIGS. 2-5.

First cable “C1” is secured by anchor member 150 of driving pulley 140 to a proximal-most portion of circumferential edge 142 of driving pulley 140 such that intermediate portion or looped portion 164 a of first cable “C1” is fixedly engaged with a portion of circumferential edge 142 of driving pulley 140. Intermediate portion or looped portion 164 a of first cable “C1” is connected to driving pulley 140 at a location off-set a radial distance from second axis “X2.”

First end portion 160 a of first cable “C1” is connected to a portion of circumferential edge 126 a of first driven pulley 122 a that is disposed on first radial side 130 a of first driven pulley 122 a. Second end portion 162 a of first cable “C1” is connected to a portion of circumferential edge 126 b of second driven pulley 122 b that is disposed on second radial side 132 b of second driven pulley 122 b.

First end portion 160 a of first cable “C1” is connected to first radial side 130 a of first driven pulley 122 a via an anchor member 180 a. Second end portion 162 a of first cable “C1” is connected to second radial side 132 b of second driven pulley 122 b via an anchor member 180 b. Anchor members 180 a, 180 b are similar to anchor member 150 described above. Each anchor member 150, 180 a, 180 b can be the same or may be different. In this way, intermediate portion or looped portion 164 a of first cable “C1” is wrapped around only first radial side 146 of driving pulley 140, as shown in FIGS. 3A, 4, and 5.

Second cable “C2” is secured by anchor member 150 of driving pulley 140 to a proximal-most portion of circumferential edge 142 of driving pulley 140 such that intermediate portion or looped portion 164 b of second cable “C2” is fixedly engaged with a portion of circumferential edge 142 of driving pulley 140. Intermediate portion or looped portion 164 b of second cable “C2” is connected to driving pulley 140 at a location off-set a radial distance from second axis “X2.” In this way, intermediate portions or looped portions 164 a, 164 b of first and second cables “C1,” “C2” are connected to a common point of driving pulley 140.

First end portion 160 b of second cable “C2” is connected to a portion of circumferential edge 126 b of second driven pulley 122 b that is disposed on first radial side 130 b of second driven pulley 122 b. Second end portion 162 b of second cable “C2” is connected to a portion of circumferential edge 126 a of first driven pulley 122 a that is disposed on second radial side 132 a of first driven pulley 122 a.

First end portion 160 b of second cable “C2” is connected to first radial side 130 b of second driven pulley 122 b via an anchor member 182 a. Second end portion 162 b of second cable “C2” is connected to second radial side 132 a of first driven pulley 122 a via an anchor member 182 b. Anchor members 182 a, 182 b are similar to anchor member 150 described above. In this way, intermediate portion 164 b of second cable “C2” is wrapped around only second radial side 148 of driving pulley 140, as shown in FIGS. 3-5.

In one embodiment, first cable “C1” includes two cables each having a first end connected to driving pulley 140 at a common point and a second end connected to first radial side 130 a of first driven pulley 122 a and second radial side 132 b of second driven pulley 122 b, respectively. Second cable “C2” may include two cables each having a first end connected to driving pulley 140 at a common point and a second end connected to first radial side 130 b of second driven pulley 122 b and second radial side 132 a of first driven pulley 122 a, respectively.

In operation, motor (Motor 1 . . . n) is energized to rotate and, in turn, drive a letting out or winding-up or a rotation of cable “C.” As cable “C” is actuated, cable “C” drives the rotation of driving pulley 140 in one of a clockwise and counter-clockwise direction. A rotation of driving pulley 140 in a first direction, indicated by arrow “A1” shown in FIG. 3A, about second axis “X2,” rotates first and second driven pulleys 122 a, 122 b via first cable “C1” about first axis “X1,” in a direction indicated by arrows “A2,” “A3” in FIG. 3A, respectively. During rotation of driving pulley 140 in the first direction, first cable “C1” is in a tensioned condition (shown in FIG. 3A) and second cable “C2” is in a slack condition. For example, as driving pulley 140 is rotated in the first direction, intermediate portion 164 a of first cable “C1” rotates with driving pulley 140 about second axis “X2.” As intermediate portion 164 a of first cable “C1” rotates, first end portion 160 a of first cable “C1” is pulled towards driving pulley 140 and, in turn, drives a rotation of first driven pulley 122 a in the same direction as the direction in which driving pulley 140 is rotating. Second end portion 162 a of first cable “C1” is also pulled towards driving pulley 140 and, in turn, drives a rotation of second driven pulley 122 b in an opposite direction as the direction in which driving pulley 140 is rotating. In this way, jaws 102 a, 102 b, which are attached to driven pulleys 122 a, 122 b, respectively, are opened about first axis “X1.”

A rotation of driving pulley 140 in a second direction, indicated by arrow “B1” shown in FIG. 3A, rotates first and second driven pulleys 122 a, 122 b via second cable “C2” about first axis “X1,” in a direction indicated by arrows “B2,” “B3” in FIG. 3A, respectively. During rotation of driving pulley 140 in the second direction, first cable “C1” is in a slack condition and second cable “C2” is in a tensioned condition (shown in FIG. 3A). For example, as driving pulley 140 is rotated in the second direction, intermediate portion 164 b of second cable “C2” rotates with driving pulley 140 about second axis “X2.” As intermediate portion 164 b of second cable “C2” rotates, first end portion 160 b of second cable “C2” is pulled towards driving pulley 140 and, in turn, drives a rotation of second driven pulley 122 b in an opposite direction as the direction in which driving pulley 140 is rotating. Second end portion 162 b of second cable “C2” is also pulled towards driving pulley 140 and, in turn, drives a rotation of first driven pulley 122 a in the same direction in which driving pulley 140 is rotating. In this way, jaws 102 a, 102 b, which are attached to driven pulleys 122 a, 122 b, respectively, are closed about first axis “X1.”

In one embodiment, as shown in FIG. 6, an end effector 200, similar to end effector 100 described above with regard to FIGS. 2-5, is shown. End effector 200 includes a first jaw 202 a and a second jaw 202 b, similar to jaws 102 a, 102 b described above. First and second jaws 202 a, 202 b are each pivotable about a first axis (not shown). End effector 200 further includes a pulley assembly 220, similar to pulley assembly 120 described above. Pulley assembly 220 is disposed within end effector 200 for actuating jaws 202 a, 202 b of end effector 200.

Pulley assembly 220 includes a first driven pulley 222 a, a second driven pulley 222 b, a driving pulley 240, a first cable “C3,” and a second cable “C4,” similar to first driven pulley 122 a, second driven pulley 122 b, driving pulley 140, first cable “C1,” and second cable “C2,” respectively, described above. In accordance with the present embodiment, first cable “C3” and second cable “C4” may be in the form of a cable loop or the like.

First driven pulley 222 a supports jaw 202 a and second driven pulley 222 b supports jaw 202 b such that jaws 202 a, 202 b rotate with driven pulleys 222 a, 222 b about the first axis. Driven pulleys 222 a, 222 b have a circular configuration and each define a circumferential edge 226 a, 226 b configured for disposal or receipt of first and second cables “C3,” “C4,” respectively.

Driving pulley 240 is spaced a lateral distance from first and second driven pulleys 222 a, 222 b. Cable “C,” connected to motor (Motor 1 . . . n), may be wrapped at least once around driving pulley 240, in the manner of a capstan so as to not interfere with first and second cables “C3,” “C4.” Driving pulley 240 has a circular configuration and defines a circumferential edge 242 configured for disposal or receipt of each of cables “C3,” “C4.”

First cable “C3” is looped or wrapped about circumferential edge 242 of driving pulley 240 and circumferential edge 226 a of first driven pulley 222 a such that, a first half 260 a and a second half 260 b of cable “C3” are in parallel relation to one another. Second cable “C4” is looped or wrapped about circumferential edge 242 of driving pulley 240 and circumferential edge 226 b of second driven pulley 222 b such that, a first half 270 a and a second half 270 b of cable “C4” are in a criss-cross or figure-eight pattern.

In use, a rotation of driving pulley 240 via motor (Motor 1 . . . n) and cable “C” causes first and second driven pulleys 222 a, 222 b to rotate, via cables “C3,” “C4,” in opposing directions to open or close first and second jaws 202 a, 202 b, which are attached thereto.

It will be understood that various modifications may be made to the embodiments disclosed herein. For example, while the driven pulleys disclosed herein have been shown and described as being connected to the proximal ends of the jaws, it is contemplated and within the scope of the present disclosure, for the driven pulleys to be operatively connected with the distal portion of the jaws. Therefore, the above description should not be construed as limiting, but merely as exemplifications of various embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended thereto. 

What is claimed is:
 1. A pulley assembly for actuating a first jaw and a second jaw, the pulley assembly comprising: a plurality of driven pulleys, each coupled to a respective jaw, each including at least two radial sides, and each rotatable about a first axis; a driving pulley rotatable about a second axis, wherein the second axis is parallel to the first axis; and a plurality of cable sections including a first cable section coupled between a first radial side of a first driven pulley of the driven pulleys and the driving pulley, a second cable section coupled between a second radial side of the first driven pulley and the driving pulley, a third cable section coupled between a first radial side of a second driven pulley of the driven pulleys and the driving pulley, and a fourth cable section coupled between a second radial side of the second driven pulley and the driving pulley, wherein each of the cable sections of the first cable section, the second cable section, the third cable section and the fourth cable section is a separate cable from the other cable sections of the first cable section, the second cable section, the third cable section and the fourth cable section, wherein a directional change in rotation of the driving pulley relieves a tension in at least two cable sections of the plurality of cable sections coupled to different radial sides of at least two of the driven pulleys and applies a tension to at least two other cable sections of the plurality of cable sections coupled to opposite radial sides of the driven pulleys than the first two cable sections.
 2. The pulley assembly as recited in claim 1, wherein the first and the fourth cable sections are tensioned and the second and the third cable sections are slackened when the driving pulley is rotated in a first direction, and the first and the fourth cable sections are slackened and the second and the third cable sections are tensioned when the driving pulley is rotated in a second direction.
 3. An end effector of a surgical tool, the end effector comprising: a first jaw and a second jaw each being pivotable about a first axis; a first driven pulley attached to the first jaw and a second driven pulley attached to the second jaw, the first and second driven pulleys being rotatable about the first axis, each driven pulley including a first radial side and a second radial side; a driving pulley rotatable about a second axis; a first cable having a first end portion, a second end portion, and an intermediate portion, the first end portion connected to the first radial side of the first driven pulley, the second end portion connected to the second radial side of the second driven pulley, and the intermediate portion connected to the driving pulley; and a second cable having a first end portion, a second end portion, and an intermediate portion, the first end portion connected to the first radial side of the second driven pulley, the second end portion connected to the second radial side of the first driven pulley, and the intermediate portion connected to the driving pulley.
 4. The end effector as recited in claim 3, wherein a rotation of the driving pulley in a first direction about the second axis rotates the first and second driven pulleys via the first cable, and a rotation of the driving pulley in a second direction, opposite the first direction, rotates the first and second driven pulleys via the second cable.
 5. The end effector as recited in claim 4, wherein during rotation of the driving pulley in the first direction the first cable is in a tensioned condition and the second cable is in a slack condition, and during rotation of the driving pulley in the second direction the first cable is in a slack condition and the second cable is in a tensioned condition.
 6. The end effector as recited in claim 3, wherein the intermediate portions of the first and second cables are connected to a common point of the driving pulley.
 7. The end effector as recited in claim 3, wherein the intermediate portions of the first and second cables are crimped to the driving pulley.
 8. The end effector as recited in claim 3, wherein the first end portion of the first cable and the second end portion of the second cable are parallel, and the first end portion of the second cable and the second end portion of the first cable cross.
 9. The end effector as recited in claim 3, wherein a proximal end of the first jaw is fixedly attached to a circumferential edge of the first driven pulley and a proximal end of the second jaw is fixedly attached to a circumferential edge of the second driven pulley.
 10. The end effector as recited in claim 3, wherein the first and second jaws include a toothed portion.
 11. The end effector as recited in claim 3, wherein the first axis is spaced a lateral distance from the second axis.
 12. The end effector as recited in claim 3, wherein the first and second cables are connected to the driving pulley at a location off-set a radial distance from the second axis.
 13. The end effector as recited in claim 3, wherein the driving pulley supports an anchor member, and the intermediate portions of the first and second cables are each looped through the anchor member of the driving pulley.
 14. The end effector as recited in claim 13, wherein the anchor member includes a hook that is attached to a circumferential edge of the driving pulley. 